Flexible container having interlocking rib and groover closure elements



Dec. .17, 1968 K. J. STALLER E CONTAINER HAVING I E AND GROOV Filed o BLOCKING E CLOSURE E ENTS Ct. 24. 1965 FLEXIBL RIB INVENTOR. KQfiE J 572:44ee

w ATTORNEYS United States Patent 3 416 585 FLEXIBLE CONTAINER HAVING INTERLOCKING RIB AND GROOVE CLOSURE ELEMENTS Karel J. Staller, Rutherford, N.J., assignor to Minigrip, Inc., Orangeburg, N .Y., a corporation of New York Filed Oct. 24, 1965, Ser. No. 504,842 4 'Claims. (Cl. 150-3) This invention relates to interlocking rib and groove elements as used for opening and reclosing a flexible container and in particular to interlocking elements having novel features which permit a discrimination between the force required to separate the elements from inside and the force required to separate the elements from the outside of the container.

Plastic or plastic-like flexible containers having reclosable elements ofler a plurality of advantages over other containers used for packaging consumer goods. But for the advantages of the reclosable flexible container to be fully utilized, the reclosable container must be economically competitive.

This invention concerns a novel feature which reduces the construction cost of the reclosable flexible container while preserving the advantages of a firm sealing structure. Recent emphasis in flexible container construction has been to develop a uniformly strong plastic film having a greatly reduced thickness. However, while the strength of the film may be adequate for normal handling purposes, an opening force may be required for the container which exceeds the film strength. This means that the film may not satisfactorily sustain the pulling force required to separate the elements.

However, according to a principal object of this invention the pulling strength required to separate the elements from the outside of the container is greatly reduced while the sealing strength of the structure at the inside of the container is increased.

A more specific object of this invention is to provide flexible closure elements which include a single tooth rib element for increasing the opening force from the inside of the container and for reducing the opening force from the outside of the container.

Another object of this invention is to provide a set of flexible closure elements which includes a rib element having a single tooth facing inwardly of the associated container and which has a single curve contour facing outwardly of the container.

It is also an object of this invention to provide a flexible reclosable container having interlocking rib and groove elements disposed about the opening thereof, which elements include a rib member having a single tooth structure facing the inner portions of the container and a double curve contour facing outwardly from the container.

It is a further object of this invention to provide a flexible reclosable container having interlocking rib and groove elements including a rib element having a single tooth structure and a groove element having a hook member cooperable with the single tooth structure of the rib element and having a substantially straightened arm portion cooperable with a similarly straightened portion of the rib element which faces outwardly of the container.

It is an additional object of this invention to provide a flexible reclosable container having interlocking rib and groove elements wherein one of said elements is provided with a single tooth structure facing the inner portion of the container and wherein the groove element comprises curved arm members for enveloping the rib element and employs a web structure extending from the outwardly disposed curved arm member to the wall of the container.

These and other objects, features and advantages of the present invention will be understood in greater detail from the following description and the associated drawings wherein reference numerals are utilized in designating illustrative embodiments [and wherein:

FIGURE 1 is a cross-sectional view of a flexible reclosable container having interlocking rib and groove elements incorporating the features of the present invention;

FIGURE 2 is a cross-sectional view of a portion of a flexible reclosable container showing interlocking rib and groove elements utilizing the single tooth double curve contour structure of this invention;

FIGURE 3 is a view similar to the view of FIGURE 2 and shows an interlocking rib and groove element wherein the rib element is of the single curve contour variety;

FIGURE 4 is a sectional view of a rib and groove element incorporating a combination of features illustrated in FIGURES 2 and 3; and

FIGURE 5 is a similar sectional view of a rib and groove element employing both a single tooth rib construction and a webbed groove construction for providing added discrimination between the force required to separate the elements from the inside and the force required to separate the elements from the outside of the container.

A principal advantage of flexible reclosable fasteners [over other more rigid structures is that they can be both firmly interlocked and readily and easily unlocked. This apparent inconsistency derives from the fact that flexible reclosable elements may be designed to provide a strong locking engagement to forces applied in all but a specified direction. When forces are applied in the specified direction, the interlocking feature no longer maintains itself and the elements easily separate. This invention, however, concerns not only developing a flexible reclosable element which opens easily due to a force applied in a specified direction but which opens more easily due to a force applied at .a particular position, namely the outside of a flexible container.

The principal locking structure of a flexible reclosable element set is the tooth or the undercut engaging surface. The tooth structure may be formed on the rib element, and the groove may have a hook member or cooperable surface for rigidly engaging the tooth structure. This type of engagement offers a firm sealing characteristic to a flexible container, however, considerable force may be required to disengage the elements depending upon the orientation of the film surfaces attached to these elements relative to the hook or engaging structure.

This invention, therefore, utilizes the undercut engaging surface characteristic for providing a firmseal to a flexible container but incorporates a novel contour for the outwardly facing surface of the rib element and introduces a novel groove structure which both aids the engagement of the inwardly facing tooth configuration but which itself offers little resistance to forces applied outwardly of the container for separating the elements.

One illustrative embodiment of this invention is shown in FIGURE 1 and comprises generally a flexible reclosable container 10 having wall portions 11 .and 12 disposed at the inner portions of the container and terminating to complete the enclosure at a point 13.

The container 10 is also provided with wall portions or flanges 1'4 and 15 which extend outwardly of the container .and which are a continuation of the inner wall portions 11 and 12. The wall portions 14 and 15 may be termed grip flanges as they are provided specifically to enable the user to pull apart the interlocking rib and groove elements.

The container 10 is provided with rib and groove ele ments 16 .and 17, respectively, which are formed integrally with the wall portions of the container. The rib element of this embodiment comprises a rounded head portion 18 3 having a double curve outwardly facing contour indicated by the numerals 19 and 20. The contour 19-20 may be referred to as having a convex portion 19 and a concave portion 20.

The rounded head 18 is also provided with a single tooth structure 21 facing inwardly of the container and having an undercut engaging surface 22 which cooperates to provide a firm engagement with the groove element 17. The entire rib element 16 is secured to the wall portion 12-14 via a shank section 23 which is formed integrally with the container film.

The groove structure of this embodiment comprises curved arm portions 24 and 25 having an inner surface 26 for enveloping the rounded head 18 of the rib element 16. The arm portions 24 and 25 have inwardly directed hook members 27 and 28 which aid in closing the container 10. Specifically, the hook member 28 engages the surface 22 of the single tooth structure 21, and in a similar manner the hook member 27 engages the double curve contour of the rib element within the concave portion 20. Therefore, inwardly of the container the tooth structure 21 resists opening thereof, and outwardly of the container the protruding or convex head portion 19 resists opening of the container.

It is apparent, however, that the distinctions between the tooth structure 21 and the double curve contour 20 provide an observable difference between the opening force required to separate the elements at the inside and at the outside of the container, with the force being greater at the inside of the container. It may be noted that varying degrees of opening resistance may be accomplished by varying the contour of the rib element facing outwardly of the container.

Many of the features of the succeeding figures are similar to those described in reference to FIGURE 1, and therefore reference numerals have been carried to those figures to avoid repetitive disclosure.

In FIGURE 2 an interlocking rib and groove element is shown which has a rib element similar to the rib eleunent of FIGURE 1 but which has .a groove element having an added novel feature. In particular, the groove element 30 is provided with curved arm members 31 and 32 as shown in FIGURE 1. However, while the arm member 32 is provided with a hook feature 33 for engaging the undercut surface 22 of the rib element 16 as provided in FIGURE 1, the arm member 31 has .an outer extremity 34 which extends in a substantially straight manner from the arm member 31 toward the wall portion 14 of the container 10. It is apparent in comparing FIGURES 1 and 2, that FIGURE 2 offers substantially the same locking characteristic at the inner points of the container 10 but offers a greatly reduced force characteristic for opening the container at points externally of the rib and groove elements. It should be understood that the straightened portion 34 of the groove element 30 is not functionless, but rather aids in maintaining the interlocking engagement of the single tooth structure 21 with the hook member 33 of the groove element 30. Therefore, the straightened arm portion 34, while offering little resistance to opening, itself, enables the hook member 33 to maintain engagement with the tooth element 21 thereby resisting opening from the inside of the container 10.

FIGURE 3 illustrates a further embodiment of this invention and, in particular, shows a rib element 35 having a single tooth structure 36 similar to the single tooth structure 21 of FIGURE 1 but having a single curve contour 37 formed at the outer facing portion of the rib element. The single curve contour as shown in FIGURE 3 tends to further ease the opening of the container at the opening or grip flanges 14 and 15, in that it does not provide a concave or undercut surface for receiving .a hook element of the groove structure. Also, since this construction provides a larger shank portion than that indicated in FIG- URE 2. less of a hinge action can take place, .and therefore more of the opening force created by the peeling of the flange 14 is transferred directly to the gripping elements.

The groove structure of FIGURE 3 has curved arm portions 38 and 39 similar to those described above. The arm portion or member 39 is equipped with a hook-like member 40 for engaging the undercut surface 41 of the tooth structure 36. Also, the arm member 38 is provided with an inwardly directed or inwardly curved extremity 42 for contacting the single curve contour of the rib element 35.

In FIGURE 4, the features of FIGURES 2 and 3 are combined and, in particular, the rib element of FIG- URE 3, indicated by the reference numeral 35, is received within the groove element 30 as shown in FIGURE 2. In FIGURE 4 the straightened portion 34 of the arm member 31 approaches more closely the configuration of the single curve contour 37 of the rib element 35. For this structure there is a very slight interlocking characteristic between the outwardly facing components 34 and 37, and the container may be opened readily by pulling apart the external flanges or grip flanges 14 and 15. However, as in previous examples, the straightened portions 34 and 37 perform the important function of assisting the interlocking characteristic of the tooth member 36 and its cooperable hook element 40.

A final embodiment of this invention is shown in FIGURE 5 and comprises interlocking rib and groove elements constructed similarly to the elements shown in FIGURE 3 with the added feature of interposing a web of flexible material, indicated by the reference numeral 43, between the curved arm portion 38 and the inner surface 44 of the external flange 15. This web member may be formed integrally with the flexible container assembly and connects directly from the point 44 to a point 45 adjacent to the inwardly directed extremit 42 of the curved arm 38. The web member 43 eases the open-ing of the interlocking assembly in that a peeling force applied to the flange 15 is transmitted directly to the hook member 42 for relieving pressure which is necessary to hold the engagement of the single tooth structure 36 and the cooperable engaging hook member 40. The elements are accordingly released.

I claim as my invention:

1. A flexible container having reclosable interlocking rib and groove elements formed at the inner surface of said container adjacent the opening thereof,

said container being opened by drawing said elements apart and being closed by pressing the elements together,

said rib element having an engaging tooth facing inwardly of the container and having a rounded head and specifically a double curve contour facing outwardly from the container,

said double curve contour having a protruding convex portion adjacent to the extremity thereof and a concave portion formed intermediate said convex portion and the base of said rib element,

said groove element having first and second curved arm portions for enveloping said rib element,

said first curved arm portion being disposed inwardly of said rib element and having a hook member formed at the outer extremity thereof for engaging said tooth of said rib element,

said second curved arm portion being disposed outwardly of said rib element and having a substantially straightened outer extremity extending adjacent to the double curve contour of said rib element and contacting the protruding convex portion thereof, whereby said container opens easily from the outside and resists opening from the inside.

2. A flexible reclosable container having interlocking rib and groove elements formed at the inner surface of the opening thereof,

said container having external flanges extending outwardly of said elements,

said flanges being drawn apart to separate said elements and to open said container thereby,

said container being closed by pressing said elements together,

said rib element having an engaging tooth facing inwardly of the container and having a rounded head and specifically a double curve contour facing outwardly from the container,

said double curve contour having a protruding convex portion adjacent to the extremity thereof and a concave portion formed intermediate said convex portion and the base of said rib element,

said groove element having first and second curved arm portions for enveloping said rib element,

said first curved arm portion being disposed inwardly of said rib element and having a hook member formed at the outer extremity thereof for engaging said tooth of said rib element,

said second curved arm portion being disposed outwardly of said rib element and having a hook member formed at the outer extremity thereof for being received within said concave portion of said rib element whereby the distinction between said engaging tooth and said double curve contour provides ease of opening from the outside and resists opening from the inside of said container.

3. A reclosable flexible container comprising: a pouch having plastic film walls and integral interlocking rib and groove elements formed at the inner surface of said walls for opening and closing said pouch,

said pouch having flanges extending from said interlocking elements outwardly of said pouch for being gripped and drawn apart to separate said elements,

said pouch being reclosable by pressing said elements together,

said rib element having a single engagement tooth thereon,

said tooth facing inwardly of said pouch and said groove having a hook member for engaging said tooth,

said rib element having a substantially smooth contour facing outwardly of said pouch and said groove element being cooperable with said smooth contour for 6 assisting in holding said interlocking elements in a closed position,

a web of flexible material formed integrally at a wall of said container adjacent to the attachment of said groove element outwardly thereof and extending to the extremity of said groove element.

4. A flexible reclosable container having interlocking rib and groove elements formed at the inner surface of the opening thereof,

said container having external flanges extending outwardly of said elements,

said flanges being drawn apart to separate said elements and to open said container thereby,

said container being closed by pressing said elements together,

said rib element having a single engaging tooth including an undercut engaging surface,

said tooth being directed inwardly of said pouch,

said groove element having the outermost extremities thereof curved inwardly for engaging said rib element,

one of said curved extremities engaging said single tooth at said undercut surface thereby holding said container in a closed position, the other of said curved extremities having a web of flexible material extending therefrom to a point on an adjacent wall of said container outwardly of said groove element,

whereby said single engaging tooth exerts a force for resisting opening of said container inwardly thereof and said web exerts a force to ease opening of said container from the outside thereof.

References Cited UNITED STATES PATENTS 3,198,228 8/1965 Naito -3 FOREIGN PATENTS 97,451 2/1961 Norway.

DONALD F. NORTON, Primary Examiner.

US. Cl. X.R. 24-201 

2. A FLEXIBLE RECLOSABLE CONTAINER HAVING INTERLOCKING RIB AND GROOVE ELEMENTS FORMED AT THE INNER SURFACE OF THE OPENING THEREOF, SAID CONTAINER HAVING EXTERNAL FLANGES EXTENDING OUTWARDLY OF SAID ELEMENTS, SAID FLANGES BEING DRAWN APART TO SEPARATE SAID ELEMENTS AND TO OPEN SAID CONTAINER THEREBY, SAID CONTAINER BEING CLOSED BY PRESSING SAID ELEMENTS TOGETHER, SAID RIB ELEMENT HAVING AN ENGAGING TOOTH FACING INWARDLY OF THE CONTAINER AND HAVING A ROUNDED HEAD AND SPECIFICALLY A DOUBLE CURVE CONTOUR FACING OUTWARDLY FRONT CONTAINER, SAID DOUBLE CURVE CONTOUR HAVING A PROTRUDING CONVEX PORTION ADJACENT TO THE EXTREMITY THEREOF AND A CONCAVE PORTION FORMED INTERMEDIATE SAID CONVEX PORTION AND THE BASE OF SAID RIB ELEMENT, SAID GROOVE ELEMENT HAVING FIRST AND SECOND CURVED ARM PORTIONS FOR ENVELOPING SAID RIB ELEMENT, SAID FRIST CURVED ARM PORTION BEING DISPOSED INWARDLY OF SAID RIB ELEMENT AND HAVING A HOOK MEMBER FORMED AT THE OUTER EXTREMITY THEREOF FOR ENGAGING SAID TOOTH OF SAID RIB ELEMENT, SAID SECOND CURVED ARM PORTION BEING DISPOSED OUTWARDLY OF SAID RIB ELEMENT AND HAVING A HOOK MEMBER FORMED AT THE OUTER EXTREMITY THEREOF FOR BEING RECEIVED WITHIN SAID CONCAVE PORTION OF SAID RIB ELEMENT WHEREBY THE DISTINCTION BETWEEN SAID ENGAGING TOOTH AND SAID DOUBLE CURVE CONTOUR PROVIDES EASE OF OPENING FROM THE OUTSIDE AND RESISTS OPENING FROM THE INSIDE OF SAID CONTAINER. 